Add support for highlight collections

[WeichhartEric]

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• [X] I have checked the issue page for duplicates
• [X] I am running the latest version (download here)

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Twitch has a feature where you can do a collection of highlighted streams and uploaded videos, which I believe it has a maximum of 100 items each.

You basically get a link like this one: https://www.twitch.tv/collections/(id)

While it is possible to access the collection to grab each link and use the mass downloader, it would be a time saver if just adding the collection was supported.

[ScrubN]

Highlights are mixed with regular VODs in the VOD Mass Downloader sorted by date.

As far as I can tell the single API request we currently make does not provide information on whether a given video is a highlight or not, just that it exists and metadata like id, views, length, etc.

[ScrubN]

Oh I missed the part about collections, I'll reopen

[ScrubN]

The API endpoints we query aren't officially documented anywhere so I'm not entirely sure if we can figure this out but hopefully we do at some point.

[lay295]

Could probably use this query. There is their old schema floating around but they disabled their introspection query so it probably won't ever be updated

https://raw.githubusercontent.com/SuperSonicHub1/twitch-graphql-api/master/schema.graphql

"""Get a single collection (playlist) item by its ID."""
  collection(id: ID!, options: CollectionOptions): Collection

[Valgard]

I'm not a C# developer, but the following GraphQL query should do the job:

query Collection {
    collection(id: "Eb9h5skuhRecGg") {
        id
        title
        items(first: 50) {
            edges {
                node {
                    ... on Video {
                        id
                        title
                        thumbnailURLs(height: 180, width: 320)
                        createdAt
                        lengthSeconds
                        owner {
                            id
                            displayName
                        }
                        viewCount
                        game {
                            id
                            displayName
                            boxArtURL
                        }
                        description
                    }
                }
                cursor
            }
            totalCount
            pageInfo {
                hasNextPage
                hasPreviousPage
            }
        }
        description
        lengthSeconds
        owner {
            displayName
            id
        }
        thumbnailURL(width: 320, height: 180)
        updatedAt
        viewCount
        type
    }
}